What are PC cards for?
Basic answer is "PC card" = "PCMCIA" or "Cardbus" expansion card
used in (mostly) older laptop computers. Current technology laptops
mostly use "Expresscard" expansion cards. They are rectangular in
shape and aproximately 2" by 3" by 1/8" thick. Expresscard cards
are about 1" by 3" by 1/8" or roughly the same size as PC Cards,
but with a smaller rectangle "cut out" of it to form a fat "L"
shape. The cards are plugged into (unlike USB devices, they usually
don't stick out except for antennas and other attachments) the PC
Card slot on laptops, usually to add features that the laptop
doesn't already have.